Generation and use of parametric X-rays with an electron linear accelerator

Parametric X-ray radiation (PXR) at energies from 15 to 30 keV was produced by a 45 MeV electron linear accelerator (LINAC) using a silicon (Si) single crystal. The appropriate conditions for generation of good monochromatic hard X-ray fields by PXR were obtained with the LINAC by theoretical calculations and experiments. The PXR intensity increased approximately linearly with the electron energy in the electron energy range of several tens of MeV. The PXR energy increased linearly with the crystal rotation angle that depended on the reflection plane and the observation angle and did not depend on the electron energy. The obtained counts of PXR increased at large observation angles although the energy decreased. The experiments used Si plates with thicknesses of 200, 300, 400, 500, 530, and 625 μm. Differences in angular distribution by the thickness of the Si plates were established. The possibility for PXR applications to material research and other fields is discussed. The off angle of the polished (cut) plane of the crystal was accurately determined using the PXR and the attenuation coefficient around the K-shell absorption edge of Zr, Nb and Mo were measured.